DataPdf files containing wells logs and a base map can viewed on electronic media that include PC, Notebook, Tablet, or Pad. Exercises can be interpreted with Power Point. Power Point drawing tools, in particular "curve". This is an effective and easy way to handle the objectives of the exercise and a means for collective viewing of results in class. Click on red box for more details. The output can also be printed,on a large frame plotter and interpreted by hand. These exercise illustrations are quite large (up to 500K in some cases) and they may take a little time to be displayed. Patience will be rewarded!!!!The clickable map below is linked to a pdf file which locates the five wells (me333, me296, me428, me313 and me 486) within the central portion of the Northern Strike Line

As an alternative this map can also be viewed by clicking on the link to a large .jpg file

A set of maps of previously interpreted wells is also provided to enable the construction of sand thickness isopachs for each of the intervals. Please refer to the basemap for the location of all the wells.

MethodsUtilize the Gulf Coast slip-slide methodto help you match the log sections and identify the same geologic events on the various wells.

To help with the interpretation of these latter logs an initial correlation has been made with the sections hung on three widespread surfaces. These are:

A basal surface correlated to the top of the P-5 silt

A surface representing the top of the P-3 silt at the center of the section and around which it is flattened

The top of the section is marked by the top of the silt that lies at the contact between the Roblecito and Pascua Formations.

Click on the thumbnail below to view the movie that demonstrates the technique that first uses the transgressive surfaces to build a framework of parasequences from these correlated surfaces and then infills the other surfaces between these as outlined below!

Technique tying well logs to interpret clastic sedimentation on coast with valley incision.

Click on links above to view YouTube and QuickTime movies of the output of the identification of log character to correlated and interpret the logs. The best way to view the YouTube movie frames is to first click on the pause symbol on the control bar and then use the mouse to grab the thumb (red circle) on the red seekbar (this tracks the progress of the movie) and move the thumb back and forth to chosen frames and so gain a better understanding of the evolving sedimentary geometries.

In contrast the best way to view the QuickTime movies is to control their motion using the arrow keys on your keyboard.

The left arrow will step the film back

The right arrow will step it forward

Normally radioactive peaks ongamma ray logs, associated with mfs, are more extensive and would have been better correlation surfaces than the transgressive surfaces but gamma ray logs were not available for much of the Guarico Sub basin. As in the movie above you should use geologic logic to infer the location of the maximum flooding surface (mfs) and correlate these on all the well logs.

Thus as shown in the film make a cross-section first correlating the prominent silts for all the wells and then correlating the sands.

Pick base of massive sands and correlate these from well to well when they occur on other logs in other wells.

Identify the sequence boundaries (SB) at base of the massive sands and correlate these from well to well.

Identify all system tracts, including the incised valley, on all well logs.

Click on links above to view YouTube and QuickTime movies of the output of the movie capturing the 3D perspective of the interpretation of the depositional setting from the well logs.

The best way to view the YouTube movie frames is to first click on the pause symbol on the control bar and then use the mouse to grab the thumb (red circle) on the red seekbar (this tracks the progress of the movie) and move the thumb back and forth to chosen frames and so gain a better understanding of the evolving sedimentary geometries.

In contrast the best way to view the QuickTime movies is to control their motion using the arrow keys on your keyboard.

The left arrow will step the film back

The right arrow will step it forward

Make a cross-section tying the silts and shales of all the wells and finally the sand geometries.

Provide an overall analysis that describes your conclusions.

As with the earlier four exercises (Exercise 1, Exercise 2, Exercise 3 and Exercise 5) to help with your interpretation of the well logs you should read the earlier sections related to the geologic setting of the La Pascua Formation and the introduction to the sequence stratigraphy of the La Pascua Formation. From these you will gain knowledge of the depositional setting of these rocks. You should combine the techniques outlined above with your understanding of the regional geology and the vertical and lateral facies relationships in near shore clastic settings (eg. shoreline, beach, stacked beaches, tidal flats, deltas) and Walther's Law. You should use these to build a depositional model and a sequence stratigraphic interpretation of the well log section.